An image forming apparatus includes: a sheet conveying mechanism which picks up recording sheets placed on a tray one by one from the tray, pinches the picked up recording sheet by rollers, conveys the recording sheet downstream of a conveyance passage by rotating the roller; and an image forming unit which forms an image on the recording sheet conveyed by operation of the sheet conveying mechanism at a record position downstream of the conveyance passage.
An image forming apparatus includes a carriage which is provided at a recording position and mounts thereon a recording head. By moving the carriage in a main scanning direction by one time, an image of a predetermined width in a sub-scanning direction along the sheet conveyance direction is formed on a recording sheet. This image forming apparatus forms an image by repeating an operation of conveying the recording sheet by the predetermined width and moving the carriage in the main scanning direction.
Usually, a motor is used as the drive source of the sheet conveying mechanism or the carriage conveying mechanism. For example, in the sheet conveying mechanism, the roller rotates while receiving the rotation force of the motor, thereby conveying a recording sheet. In the carriage conveying mechanism, the carriage moves in the main scanning direction along a guide shaft by the drive force of the motor.
By the way, in such kind of conveying mechanism using the motor, if the motor continues to operate for a long time, the motor becomes a high temperature due to heat generated by the motor. This may cause malfunction, a failure, and degradation of durability of the motor. In order to circumvent this problem, for example, in a related-art apparatus, if a motor becomes a high temperature exceeding an allowable temperature, the motor is stopped, etc., for suppressing the operating rate of the motor.
For example, JP-A-2006-246670 describes a related-art printer apparatus which detects the motor temperature, calculates the stop time of the motor from the detected motor temperature, and stops the motor for the calculated stop time.
However, in the related-art printer apparatus described in JP-A-2006-246670, if the motor becomes a high temperature, the motor stops automatically. Thus, if printing operations continue successively, the user can not use the printer and the user may be discontented with the situation. That is, even if only few pages to be printed remain, the related-art printer apparatus makes a transition to the stop state for the reason that the motor is at a high temperature. Thus, the user has to wait for output of the print result for few remaining pages and this is inconvenient for the user.